Hydraulic rock-drill.



PATENTED Nov. 5, 1907.

APPLIUATION FILED MAY 8. 1905.

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N6. 869,893. PATENTBD NOV. 5, 1907.

G. B. GJUKB'.

HYDRAULIC ROCK DRILL. APPLICATION FILED mu 8. 1905.

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PATENT ornren.

GEORG EMIL GJUKE, OF TRELLEBORG, SWEDEN.'

HYDRAULIC ROCK-DRILL.

Specification of Letters Patent.

Patented Nov. 5,1907.

Application filed May 8. 1905- Serial No. 259,258-

To all whom it may concern: '4

Be it known that I. GEoRe EMIL GJUKE, mining-engineer, a subject of Sweden, residing at Trelleborg, in the Province of Scania, Sweden, have invented new and useful Improvements in Hydraulic Rock-Drills, of which the following is a. specification.

The present invention which relates to a hydraulic rock-drill, is illustrated in the accompanying drawing where I Figure l is a longitudinal section, Fig. 2 a cross-section on the line 2-2 of Fig. 1; Fig. Sis a cross-section on the line 33 of Fig. 1 and Fig. 4 is a detail view on an enlarged scale of the air-pump portion of the devices shown at the extreme right of Fig. 1 in the chamber i.

The apparatus consists of a casting a with guides at for guiding the apparatus proper when being fed forward. said feeding being effected by means of a screw [7 journaled in the casing a and provided with a crank. The drill carrier or holder (2 is situated at the extreme end of the piston rod 6 of a piston e movable in a cylinder (Z, said piston being actuated by a spring, compressed air, or the like, forcing the piston outwards. In the apparatus illustrated in the drawing the said action is exerted on the piston by means of compressed air inclosed in the inner end i of the cylinder d and kept at a constant pressure by means of a small air-pump composed of the hollow tube 5/, piston-rod bore f, and valve and packing shown fully in detail in Fig. 4. The piston at the opposite end in relation to the piston rod 0 is provided with a rod e located within the chamber 1 and provided with a longitudinal bore f surrounding the pump which is composed of a tube 9 provided with a valve 1; and packing h, the outer end of said tube be ing screwed through the cylinder head and projecting outside it, so that the tube g may be adjusted at will according as a greater or less pressure is wanted in the chamber 1'. If the air in this chamber becomes rarefied through leakage, the air in front of the packingsaid air being compressed when the piston e occupies the position shown in Fig. 1will force aside thepacking h and enter the chamber '5. When the piston 12 is subsequently thrown forwards, a vacuum will be created in front of the packing h which is consequently forced against the wall of the bore f, and the outer air operating through the tube g will open the valve is and enter to the inner end of the said bore f of the piston rod e,

to be subsequently forced into the chamber 2', in the manner just mentioned, at the receding movement of the piston. This is repeated until the air contained in the chamber-i on having acquired the proper pressure forces the packing it against the wall of the bore and thus prevents communication between the outer air and the chamber 't'.

The cylinder is provided with an inlet port I and an outlet-port or, formed in and through the annular wall of such cylinder-the port Z communicating with an annular chamfer or groove 1 in the cylinder wall, and the port m, with a like groove or chamfer m, and as the construction of the two are similar, save that the groove 1 has its outer wall cut away where it passes under the small relief cylinder 8 so as to communicate therewith as is clearly shown at q in Fig. 1 and m and m are clearly shown in Fig. 3, any further illustration of Z is deemed superfluous. The pressure-fluid which actuates the device is admitted to the cylinder by the inlets Z and l and exhausted by way of m and m, by way of a cylindrical valve 0 provided with peripheral ports 71., which is reciprocated back and forth by abutment, first against the pistonhead a, and second in the opposite direction by abutment in like manner against the opposite piston-head e, which heads are connected together so as to form a double-headed piston by the central smaller portion or central piston-rod 6 and the ports a when the valve is at the extreme limit of travel to which it is driven by impact against the end thereof the pistonhead e are in communication with m, and'when at the opposite limit of travel to which it is driven by impact with the head e,.are in communication with Z; and it will thus be seen that when the parts are in the position shown in the drawing, the cylindrical space p'surrounding the piston-rod between the two pistonheads is in communication with the outlet or exhaust or by way of the groove m by way of the cylindrical valve-ports u, but when the piston owing to the expansion of the air in the chamber i-is thrown forwards, it will push the valve forwards and bring the space p into communication with the pressure con- (luit through the inlet Z, so that the pressure-fluid can flow in and force back the piston. Should the pressure in the space 1) become too great-i. e. greater than that in the pressure conduit, which may happen if the drill on failing to strike the rock is thrown too far forward, the cylinder might burst unless a device he provided for taking up the pressure. This device consists of a piston 15 moving in a cylinder s and actuated at the drill end by a spring 1", and at the rear end by a spring r. The cylinder 5 by means of an aperture q is in permanent communication with the space 1) by way of the slant face 2, and the annular orifice x of the valve 0, which are hereinafter more fully described, so that when the pressure therein becomes too great the pressure-fluid will flow through the said aperture q into the cylinder s and force the piston it against the spring r to the rear which thus takes up a portion of the pressure. The other or rear end of the cylinder s is in permanent communication with the pressure conduit l,'which communicates with the annular groove 2 through a passage q formed by a part of such annular groove Z and it will be seen that when the parts are in the position shown in Fig. 1, that if now the double headed piston is driven forward, the valve 0 will remain stationary and that upon the outthrow of the drill or failure to strike the rock, the compressed air will enter by way of the port q and force back the piston t against the pressure of the spring 1" in such mannerthat the pressure will be taken up by the spring and the elasticity of the compressed air in the conduit leading to the cylinder as herein more fully described, so that there willbe no danger of bursting the cylinder. For this purpose the orifice x in the valve 0 communicates with the portion of the cylinder in communication with the relief piston port g by reason that the abutting face of the piston head 6 is provided with an annular groove 2, broken by studs z to receive the shock of impact with the valve 0 and drives the same rearward into the exhaust position shown in Fig. 1.

The rotation of the drill is produced by means of a device already known. The rod 6 for this purpose is provided with threads of great pitch, on which is screwed a ratchet it. When the piston is thrown back the ratchet u is prevented from revolving by means of a pawl a, the piston consequently being rotated instead, but in the forward movement when the ratchet rotates in the other direction the pawl cannot retain it, and for this reason the piston together with the drill can move forwards without rotating motion.

As before stated the valve 0 is reciprocated back and forth in the cylinder by the abutment against the same of the face of the piston c which gives it its forward movement, and the like abutment against it of the rear face of the enlarged portion c of the piston rod (2 This face of the enlarged portion 6 merges gradually into the small central portion 0'' of the piston rod as shown in Fig. 1 at .2, so that communication is had at all times with the interior of the valve 0 by way of the annular passage or space .r around the piston rod c and by this means it will be seen that the pressure on the piston t by way of the passage (1 is always the same as it is in the valve 0 and the annular chamber p. Consequently, when upon the forward or working movement of the piston while the exhaust is still closed by the valve 0, should there be a compression of the motor fluid in the cylinder in front of the piston c, this excess pressure will. be brought to bear upon the forward end of the relief piston t by way of the passage q, which pressure will force back such relief piston it against the rear relief spring 1", which spring will thus take up apart of such excess pressure, while the rest will be taken up by the motor fluid in the inlet Z and its connections.

The apparatus operates as follows: When the inlet Z is placed in communication with the pressure conduit, the entering pressure-liquid forces back the piston c which carries with it the valve 0 so that the inlet Z is shut off and the outlet m opened, The air compressed by the return movement of the piston in the chamber 41 now throws the piston forwards, the pressure liquid being consequently forced out through the outlet m and the valve pushed forwards so that the inlet Z will again be opened and the outlet closed, etc.

What I claim is:

1. In a device of the class described, a cylinder, a piston, 21 fluid pressure chamber on the axial line and to the rear of the cylinder in communication with the rear portion of the cylinder, and means actuated by the piston for drawing atmospheric air into the fluid pressure chamber upon the working stroke of the piston and compressing it therein upon the rearward or back stroke.

2. In a device of the class described, a cylinder, a piston, a fluid pressure chamber on the axial line and to the rear of the cylinder and in communication therewith, means actuated by the piston for drawing atmospheric air into the fluid pressure chamber, and means for regulating the pressure to be maintained in the fluid pressure chamber.

3. A rock-drill comprising a-cylinder, a drill carrier, a carrier supporting piston reciprocating in the cylinder and actuated in the-working direction by a compressed elastic fluid, the pressure of which is stored by the movement of the piston in the opposite direction, and valve means for admitting a fluid under pressure to the cylinder forward of the piston so as to drive the same rearward in the nonworking direction and for permitting the escape of such pressure fluid at the conclusion of the non-working stroke.

4. In a rock-drill a cylinder, a drill supporting double headed piston reciprocating in the cylinder actuated in the working direction by power stored by its own movement, and in the other or non working direction by a pressure fluid alternately admitted to and discharged from the part of the cylinder surrounding the piston-rod between the piston heads, an auxiliary pressure relieving cylinder in connection at either end with the main cylinder, and a spring balanced piston in the relieving cylinder.

5. A roclcdrill comprising a cylinder, a drill supporting double headed piston reciprocating in the-cylinder actuated in the nonworking direction by a pressure fluid alternately admitted to and discharged from the part of the cylinder surrounding the smaller central portion of the doubleheaded piston, and actuated in the working direction by power stored by its own movement in the nonworking direction, a hollow red at the rear end of the piston in communication with a fluid .pressure chamber, a hollow stationary piston rod secured to the wall of the fluid pressure chamber, in communication at the outer end with the atmosphere and open at the inner end, a check-valve for said hollow stationary piston rod and a backwardly faced selfpacking flexible washer or packing ring carriedby the hollow stationary piston-rod located in the hollow of the piston-rod.

6. In a device of the class described, a cylinder having an inlet port and an exhaust port in the annular wall, a double headed piston the heads of which are of difierent diameters and secured to a central piston-rod reciprocating in the cylinder. an-annular perforate walled valve surrounding the piston-rod between the pistonheads reciprocated thereby, an extension of the piston-rod extending rearward from the main piston having a central longitudinal open ended here, an auxiliary pressure chamber in which such piston-rod extension reciprocates back and forth, a hollow rod provided with a screw-thread secured into the wall of the auxiliary pressure chamber and extending into the bore of the piston-rod extension, an inwardly opening aircheck-valve located in the bore of the hollow screw-rod and a backwardly faced packing ring carried by the screw-rod and fitting snugly in the bore of the pistonrod.

7. In a device of the class described, a cylinder having an inlet port and an exhaust port in the annular wall, a piston rod, a piston head at one end or the piston-rod and a piston at the other end of the piston-rod reciprocating in the cylinder, and annular valve surrounding the piston-rod between the piston-heads, a relief chamber adjacent to the main cylinder extending longitudinally of the same, a piston normally located in the center of such chamber and keptin such central position by means of springs, a port always in communication with the cylinder at the forward end of the relief chamber, and a like port located in the other end of the relief chamber wall brought into and out of communication with the cylinder by the action of the valve.

8 In a device of the class described, a cylinder having an inlet port and an exhaust port in the annular wall, a piston-rod reciprocating in the cylinder, two heads secured to the piston-rod, an annular perforate-walled valve surrounding the piston-rod between the piston-heads, an extension of the piston-rod extending rearward from the main piston having a central longitudinal open ended bore, a closed auxiliary pressure chamber in which such pistonrod extension rcciprocates back and forth, in communication only with the near end of the cylinder, a hollow rod provided with a screw thread secured in the wall of the auxiliary pressure chamber and extending into the bore of the pist0n-rod extension, an inwardly openingair-checkvalve located in the bore of the hollow screw-rod, a back wardly faced packing ring carried by the screw-rod and fitting snugly in the bore of the piston-rod, a relief chamber adjacent to the main-cylinder and extending longitudinally 01E the same, in communication therewith at either end and a piston normally located in the center of such chamber and kept in such position by a spring on either side.

In testimony whereof I have signed my name to this specification in the presence of two subscribing; witnesses.

GEORG EMIL GJUKE. Witnesses Gosm OSCARBIJRG, S. ln'r'rnnssox. 

